Re: BUG #1518: Conversions to (undocumented) SQL year-month - Mailing list pgsql-bugs

Tom> In order to support the spec *exactly*, we would have to.
    Tom> For instance we cannot presently tell the difference between
    Tom> '13 months' and '1 year 1 month' ... they both end up stored
    Tom> as '13 months'.  I can't say that I find this very important,
    Tom> but it does put limits on how exactly we can emulate the
    Tom> spec.

Which is where my comment about EXTRACT comes in.  They can both be
stored as 13 months, but EXTRACT (MONTH FROM ...) should return 1
month or 13 months as appropriate.  Surely this isn't a problem, you
know the type of the interval?

So you _can_ emulate the spec, you just don't use the same internal
representation that a naive implementation of the spec would...

           -roy